lcl-cocoa: restoring the items checked status after the sort, if WS needs some extra assistance for that. bug #39121. potential resolution for #38137

git-svn-id: trunk@65351 -

lcl/include/customlistview.inc

@@ -1038,6 +1038,8 @@ procedure TCustomListView.SortWithParams(ACompareFunc: TListSortCompare);
 var
   FSavedSelection: TFPList;
   FSavedFocused: TListItem;
+  FSavedChecked: TFPList;
+  FSavedCheckItem: TListItem;
   i: Integer;
   AItemIndex: Integer;
 begin
@@ -1048,6 +1050,7 @@ begin
   begin
     Include(FFlags, lffItemsSorting);
     FSavedSelection := TFPList.Create;
+    FSavedChecked := nil;
     try
       if (ItemIndex >= 0) then
         FSavedFocused := Items[ItemIndex]
@@ -1061,6 +1064,15 @@ begin
             if Items[i].Selected and (Items[i] <> Selected) then
               FSavedSelection.Add(Items[i]);
       end;
+      if (TWSCustomListViewClass(WidgetSetClass).RestoreItemCheckedAfterSort(Self))
+        and Items.WSUpdateAllowed
+        and not OwnerData then
+      begin
+        FSavedChecked := TFPList.Create;
+        for i := 0 to Items.Count - 1 do
+          if Items[i].Checked then
+            FSavedChecked.Add(Items[i]);
+      end;
 
       Items.FCacheIndex := -1;
       Items.FCacheItem := nil;
@@ -1084,6 +1096,19 @@ begin
             TWSCustomListViewClass(WidgetSetClass).ItemSetState(Self,
               AItemIndex, Items[AItemIndex], lisSelected, True);
         end;
+
+        if FSavedChecked <> nil then
+        begin
+          for i := 0 to FSavedChecked.Count - 1 do
+          begin
+            FSavedCheckItem := TListItem( FSavedChecked[i] );
+            // todo: this is inefficient, because FSavedCheckItem.Index must be called again
+            TWSCustomListViewClass(WidgetSetClass).ItemSetChecked(Self,
+              FSavedCheckItem.Index, FSavedCheckItem, True);
+          end;
+          FSavedChecked.Free;
+        end;
+
       end;
     finally
       FreeThenNil(FSavedSelection);

lcl/interfaces/cocoa/cocoawscomctrls.pas

@@ -202,6 +202,7 @@ type
     class procedure SetScrollBars(const ALV: TCustomListView; const AValue: TScrollStyle); override;
     class procedure SetSort(const ALV: TCustomListView; const {%H-}AType: TSortType; const {%H-}AColumn: Integer;
       const {%H-}ASortDirection: TSortDirection); override;
+    class function RestoreItemCheckedAfterSort(const ALV: TCustomListView): Boolean; override;
     (*class procedure SetViewOrigin(const ALV: TCustomListView; const AValue: TPoint); override;
     class procedure SetViewStyle(const ALV: TCustomListView; const AValue: TViewStyle); override;*)
   end;
@@ -1675,9 +1676,14 @@ class procedure TCocoaWSCustomListView.SetSort(const ALV: TCustomListView;
   const ASortDirection: TSortDirection);
 var
   lTableLV: TCocoaTableListView;
+  lCocoaLV: TCocoaListView;
   lNSColumn: NSTableColumn;
+  Cb: TLCLListViewCallback;
 begin
   if not CheckColumnParams(lTableLV, lNSColumn, ALV, AColumn) then Exit;
+  if not CheckParamsCb(lCocoaLV, lTableLV, cb, ALV) then Exit;
+
+  cb.checkedIdx.removeAllIndexes;
   lTableLV.reloadData();
   { //todo:
     lNSColumn.setSortDescriptorPrototype(
@@ -1689,6 +1695,12 @@ begin
   );}
 end;
 
+class function TCocoaWSCustomListView.RestoreItemCheckedAfterSort(
+  const ALV: TCustomListView): Boolean;
+begin
+  Result:=true;
+end;
+
 { TCocoaWSProgressBar }
 
 class function TCocoaWSProgressBar.CreateHandle(const AWinControl: TWinControl;

lcl/widgetset/wscomctrls.pp

@@ -174,6 +174,10 @@ type
       const ASortDirection: TSortDirection); virtual;
     class procedure SetViewOrigin(const ALV: TCustomListView; const AValue: TPoint); virtual;
     class procedure SetViewStyle(const ALV: TCustomListView; const Avalue: TViewStyle); virtual;
+    // if returns true, then LCL will call SetItemChecked after calling SetSort
+    // for every item previously checked. Only widgetsets that don't support native sort
+    // AND/OR that don't support native checkboxes should have this method return true
+    class function RestoreItemCheckedAfterSort(const ALV: TCustomListView): Boolean; virtual;
   end;
 
   TWSCustomListViewClass = class of TWSCustomListView;
@@ -781,6 +785,12 @@ class procedure TWSCustomListView.SetViewStyle(const ALV: TCustomListView; const
 begin
 end;
 
+class function TWSCustomListView.RestoreItemCheckedAfterSort(const ALV: TCustomListView
+  ): Boolean;
+begin
+  Result := false;
+end;
+
 class procedure TWSCustomListView.SetItemsCount(const ALV: TCustomListView; const Avalue: Integer); 
 begin
 end;